Fibrous product and method of making the same



Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE MAX H: KLIEFOTH, OF MADISON, WISCONSIN, ASSIGNOIt TO U. I. BURGESS LABORA- TORIES, INC., OF MADISON, WISCONSIN, A CORPORATION OF DELAWARE FIBROUS PRODUCT AND METHOD OF MAKING THE SAME No Drawing.

This invention relates to a method of making a composite product composed of a fibrous material and a binding material. The fibrous product may be in the form of loose pads or 1t may be in the form of hard% dense, waterrepellent compositions or 0 intermediate densities. Board or other shapes may be produced. My process is especially suitable for the making of fibrous mats or boards used :for embossing.

At the present time there are several methods used to make fibrous products containing a binding substance such as pitch, asphalt, and the like. One method consists in fabricating the fibrous product and then saturating it by immersing it in a hot molten bath of the binding substance. This method is unsatisfactory for many purposes as the satu rating material does not penetrate the fibrous product thoroughly. In recent years asphalt and pitch emulsions have been used to produce a product of this type. The emulsion is mixed with the paper pulp or other fibrous product in the beater and the mixture of pulp and emulsion may either be run over a suitable paper machine in the usual manner or the pulp may be molded. Such emulsions, however, are ex ensive. In the Weiss Patent N o. 1,461,33 a method is described and claimed wherein a mixture of fibrous material and a hard, solid pitch or other binder is shredded in a suitable shredder and the intimate mixture of shredded pulp and binder, after screening, is laid down on a screen in the form of a blanket and then subjected to heat and pressure to form a wallboard and to simultaneously melt the binder to saturate the fibers. In the method disclosed and claimed in the Weiss Patent 1,7 37 ,282, the powdered binder, such as pitch and asphalt, is sprinkled onto a wet pulp web coming from the wet end of a paper machine.

The combined wet pulp web and powdered binder is then fabricated into the desired product. On heating and pressing the binder melts and saturates the final product. All of these methods have advantagesfor certain purposes.

I have discovered a novel method for introducing the binder into the fibrous product Application flied June 21, 1930. Serial No. 462,924.

which has certain advantages which will become apparent as the description progresses. It has the decided advantage of lowerlng the cost over the competing methods which are now in commercial use.

In carrying out my invention the fibrous material and binding a ent are .preferably mixed in a shredder w ich pulverizes the binder and shreds the fibrous material into a mass of fibers intimately mixed with small particles of binder. The fibers leaving the shredder have the fine particles of the binder attached to them so that they are not easily separated therefrom. This intimate mixing may also be accomplished though not as efiiciently by first shredding the fibrous material and powdering the bindin material to a fine powder. These two su stances are then thoroughly mixed in order to secure the intimacy of contact needed. Although I may use wood waste in the form of shavings, sawdust, chips, cork or the like as the fibrous material, I prefer to use paper pulp, cotton, or similar high-grade. fibrous material. For embossin boards and especially where deep em ossing is required, I prefer a long fibered stock such as kraft pulp. It is also possible to use fibrous material not of a cellulosic nature such as hair and asbestos. As the binding agent I may use pitch-like materials such as solid coal-tar pitch, asphalt, rosin, certain Waxes and combinations thereof, or similar Water-repellent materials, or any other suitable binding material which melts at a temperature not dematerial is substantially dry, preferabl containing 10% or less of moisture. The fi brous material and binder are each placed in the shredder or other suitable mixing machine in a substantially dry and solid condition and the shredding or mixing operation roduces an intimate mechanical admixture o the two materials. At the same time, it shreds the woody or other fibrous materials to more or less separate the individual fibers, and pulverizes the binding agent. For reasons which will become apparent hereinafter, it is desirable to add the binder to the shredder in granular form so that it will be practically entirely powdered during the shredding operation. If the shredder warms up sufficiently to cause the binder to ball up, it may be kept cool by means of an air stream passing through it with the material being shredded.

After the shredding or mixing operation, the mixture of fibrous material and binding agent is preferably screened to separate the particles of binding agent which are still too coarse to adhere to the fibers. During the shredding operation the finely divided binding agent becomes attached sufficiently to the fibers to prevent a separation during the subsequent operations. The screen is sufficiently fine to retain practically all of the fibers but allows the norradhering particles of bindin agent and a few fibers to pass throug If the pieces of binder are too large when they are fed to the shredder then some of the particles coming from the shredder will be too coarse to pass through the screen and will be retained with the fibers. Although continued shredding breaks down the large particles it also cuts up the fibers which is undesirable. The material passing through the screen may be returned to the shredder.

The fibrous material passing through the shredder and which has been suitably pulverized and shredded and in accordance with this invention may be conveyed directly to a tank in which it may be suspended in water. I prefer, however, to ass the mixture of fibers and adhering binding material through an oven heated to such a temperature that the binding material becomes slightly softened and adheres more firmly to the fibers. The product should not be heated to such a temperature that the entire mass sticks together or to such a temperature that the fibers become brittle. The heating of the mixture of fibers and binding substance to efi'ect better adherence between the two prevents losses of binding substance in the subsequent operation.

Although it is possible to use the intimate mixture of shredded fibers and binder directly to form boards, etc., I find that the binding substance tends to stick to the mold or faces of the press. This sticking tendency is overcome by using a wet mixture of fibers and binder. By my process I can form water suspensions of vmixed fibers and binder at a low cost, and thus avoid the use of the expensive pitch or asphalt emulsions of prior processes.

In carrying out this process, the screened, intimate mixture of fibrous material and binding agent is suspended in water. A paddle mixer may be used in forming the suspension. To. put the fibrous mixture in better condition for running over the wet end of a. paper machine it is desirable to give the mixture a light beating, sometimes called combing.

This combing prevents the segregation of bunches of the mixed fibrous material and results in a uniform suspension which is necessary to obtain the best results. If the particles of binder do not adhere sufliciently to the fibers during the beating operation, these particles become detached, settle to the bottom, and are lost in the waste water. As previously described, this loss is decreased by heating the intimate mixture of fibers and binding agent to cfiect better adherence. After thus combing the product it may be utilized in several ways.

The suspension or slurry of the mixture of fibers and binding agent may be run onto a suction screen as in pulp molding operation. The molded article after drying may be beated to melt the binding substance and to thoroughly saturate the fibers to secure the maxi mum of water resistance. Pressure also may be used with or without heat to density the final product. The suspension of fibers and binding substance may be used to form wall and insulating boards, insulating pads and the like.

I prefer, however, to utilize the suspension of fiber and adhering binding substance in a paper machine and form fibrous products therewith. After drying, these fibrous products may be heated to still higher temperatures if necessary to melt the binding substance and saturate the fibers to form a waterrepellent product. A dense product is formed by applying pressure during or after the saturating operation. The suspension as described is especially suitable for use with the machine described in the lNeiss Patent 1,737,283 to form the various fibrous prodnets and especially some of the products claimed and described in Weiss Patent 1,737,282. The resulting product may be left in the form of a porous absorbent pad which may subsequently be pressed as previously described to form a dense, hard, water-repellent board. After heating and compressing the board, it is allowed to cool and it may then be cut to any desired dimensions.

It is desirable for some purposes and especially for embossing boards to have clay or other similar filler in the stock. I have found that the filler may be added to the mixture of fibrous material and binding material prior to or during the shredding operation to be thereby intimately mixed therewith. The filler also may be added in the heater or paddle mixer. The filler, binderand very short fibers form the plastic material which must be present in embossing stock. The filler is preferably added during the shredding operation since this produces a more intimate mixture with the fibers and binding agent and furthermore hel s prevent the binder from adhering to the s redder and screen.

Where the final product must be harder and the surface must be smooth, these properties may be obtained by introducing sodium silicate into the stock. The sodium silicate as such may be used or it may be precipitated by means of aluiii as is well known to those skilled in the paper makin art. The sodium silicate preferably is added to or precipitated in the pulp slurry.

I claim l. The method of manufacturing a fibrous product which comprises heating an intimate mixture of fibers containin not more than 10 per cent moisture and finely-powdered, adhering, solid fusible hinder sulliciently to cause said binder to adhere more firmly to said fibers, suspending said mixture of fibers and binder in water, and forming a fibrous product from the wet pulp thus produced.

2. he method of manufacturing a waterresistant fibrous product which comprises heating an intimate mixture of cellulosic fibers containing not more than 10 r cent moisture and finely-powdered, ushering, fusible, gitch-like, solid water-repellent binder su ciently to cause said binder to adhere more firmly to said fibers, beating said mixture of fibers and binder while suspended in water, forming a moist web from the pulp sus ension thus produced, forming a product rom said web, heating said product to remove moisture, and compressing said product while hot to densify it and to saturate the fibers with said binder.

3. The method of manufacturing a fibrous product which comprises shredding fibrous material containing not more than 10 per cent moisture with a solid fusible binder to produce an intimate mixture, heatin said mixture sufiiciently to cause said bin er to adhere more firmly to said fibers, suspending said mixture in water, forming a fibrous product from the wet pulp thus produced, and drying said product.

4. A method of manufacturing a fibrous product which comprises shredding fibrous material containing not more than 10 per cent moisture with a solid fusible binder to produce'an intimate mixture, removin the coarse particles of said binder theref rom, heatin sai mixture sufiiciently to cause said binder to adhere more firmly to said fibers, suspending said mixture in water, and forming a fibrous product from the wet pulp thus produced.

5. The method of manufacturing a fibrous product which comprises shredding fibrous material containing not more than [0 per cent moisture with a solid fusible hinder to produce an intimate llllXtlll't, suspending said mixture in water, and forming ii lilirous roduct from the. wet pulp thus produced.

i. The method of iininu iicturing it lihrous product which comprises shredding ii mixture of cellulosic fibrous material containing not more than 10 er cent moisture, filler, and a solid fusible inder to produce an intimato mixture, suspending said mixture in water, and forming a fibrous product from the wet pulp thus produced.

7. The method of manufacturing a librous product which comprises shredding librous material containing not more than 10 per cent moisture with a solid fusible binder to produce an intimate mixture, beating a suspension of said mixture in water, forming a moist web from the pul suspension prod need, and forming a prod iict from said web.

8. The method of manufacturing a fibrous product which comprises shredding fibrous material containing not more than 10 per cent moisture with a solid fusible binder to produce an intimate mixture, heatin said mixture sutficiently to cause said bin er to soften and to adhere more firmly to said fibers, suspending said mixture of shredded fibers and binder in water, forming a moist web from the pulp thus reduced, forming a product from said web, eating said prodnot to remove the moisture and to saturate the fibers with said binder.

9. The method of manufacturing a fibrous product which comprises shredding fibrous cellulosic material containing not more than 10 per cent moisture with a solid fusiblepdchlike binder to produce an intimate mixture, removin the non-adherin particles of said binder -t erefrom, suspen ing said mixture in water, and forming a fibrous product from the wet ulp thus produced.

10. e method of manufacturin fibrous product which comprises paper pulp containing not more than 10 per cent moisture with a solid fusible, pitch-1i e, water-repellent binder to produce an intimate mixture heating said mixture sutficiently to cause said itch-like binder to soften and adhere more rmly to said fibers, beating a suspension of said mixture in water, forming a moist web from the pulp suspension thus pro duced, forming a product from said web heating said product to remove moisture an compressing said product while hot to density it'and to saturate the fibers with said binder.

11. The method of manufacturin a den fibrous product which comprises s redding kra ft paper pulp containing not more than 10 percent moisture with a solid fusible, pitch like, water-repellent binder to produce an intimate mixture, screening said mixture to remove the non-adliering particles of said binder therefrom, beating a suspension of said mixture in water, forming a moist web from the pulp suspension produced, formin" a product from said web, heating suicl prodiirt to remove moisture, and com )rcssing ul product while hot to form a dense rodurt and to saturate the libors with said binder.

12. In the herein-described proccs fo a dense redding nufacturin a fibrous product from fibrous iiiiitcrial and zi fusible binder, the combination of steps which comprises heating an ntimate mixture of shreddlegl fibrous mgitsietrgla 'n'n not more than or cen m D 5 z iii d i dlie ing powdered, soli d fusible binder to cause said binder to soften sufiic1ently to adhere more firmly to said fibers, and beating a suspension of said rticnxture of fibers and adb'nder in wa r.

m lgi ln the herein-described process for manufacturing a fibrous product, the combination of steps which comprises shredding fibrous material containing not more than per cent moisture with H SOlId fusible binder to produce an intimatetmixture, and suspendid mixture in we er. lZ In the herein-described process for manufacturing a fibrous artlcle, the ste which comprises shredding a mlxture of brous material containing not more than 10 per cent of moisture, a solid fusible binder, and filler to produce an intimate mixture.

15. An article of manufacture compnsm an irregular, intertangled mass of fibers an irregularly dispersed discrete part cles of a fusible binder, said particles of binder adhering to said fibers and being adapted for subsequent fusion to bind the fi rous mass together in the fixedhformfulltlgiatgy gieS1l1I;-9l.re

ereo a x In testimony w M- H- KLI F TH- DISCLAIMER 1,875,018.Ma2: H. Kliefoth, Madison, Wis. FIBROUB PRODUCT AND METHOD or MAKING THE SAME. Patent dated August 30, 1932. Disclaimer filed July 7, 1934, by the assignee, The Patent and Licensing Corporation.

Hereby enters this disclaimer to that part of the specification of the aforesaid Letters Patent which consists of claims 5, 6, 7, 13, 14, and 15 which are in the following words, to wit: a

5. The method of manufacturin a fibrous product which com rises shredding fibrous material'containing not more fiaan 10 or cent moisture, witii a solid fusible binder to produce an intimate mixture, suspen ing said mixture in water, and forming a fibrous roduct from the wet pulp thus produced.

6. he method of manufacturing a fibrous product which comprises shredding a mixture of cellulosic fibrous material containing not more than 10 per cent moisture, filler, and a solid fusible binder to produce an intimate mixture, suspendin said mixture in water, and forming a fibrous product from the wet pulp thus pro need.

7. The method of manufacturing a. fibrous product which com rises shreddin fibrous material containing not more than 10 per cent moisture wit a solid fusible binder to produce an intimate mixture, beating a suspension of said mixture in water, forningba moist web from the pulp suspension produced, and forming a product from am we 13. In the herein-described process for manufacturing a fibrous product, the combination of steps which comprises shredding fibrous material containing not more than 10 per cent moisture with a solid fusible binder to produce an intimate mixture, and suspendin said mixture in water.

14. In t e herein-described process for manufacturing a fibrous article, the step which comprises shredding a mixture of fibrous material containing not more than 10 per cent of moisture, a solid fusible binder, and filler to produce an intimate mixture.

15. An article of manufacture comprising an irregular, intertan led mass of fibers and irregularly dispersed discrete particles of u fusible binder, said particles of binder adhering to said fibers and being adapted for subsequent fusion to bind the fibrous mass together in the fixed form ultimately desired.

[Oflicial Gazette August 7, 1.934.]

nufacturin a fibrous product from fibrous iiiiitcrial and zi fusible binder, the combination of steps which comprises heating an ntimate mixture of shreddlegl fibrous mgitsietrgla 'n'n not more than or cen m D 5 z iii d i dlie ing powdered, soli d fusible binder to cause said binder to soften sufiic1ently to adhere more firmly to said fibers, and beating a suspension of said rticnxture of fibers and adb'nder in wa r.

m lgi ln the herein-described process for manufacturing a fibrous product, the combination of steps which comprises shredding fibrous material containing not more than per cent moisture with H SOlId fusible binder to produce an intimatetmixture, and suspendid mixture in we er. lZ In the herein-described process for manufacturing a fibrous artlcle, the ste which comprises shredding a mlxture of brous material containing not more than 10 per cent of moisture, a solid fusible binder, and filler to produce an intimate mixture.

15. An article of manufacture compnsm an irregular, intertangled mass of fibers an irregularly dispersed discrete part cles of a fusible binder, said particles of binder adhering to said fibers and being adapted for subsequent fusion to bind the fi rous mass together in the fixedhformfulltlgiatgy gieS1l1I;-9l.re

ereo a x In testimony w M- H- KLI F TH- DISCLAIMER 1,875,018.Ma2: H. Kliefoth, Madison, Wis. FIBROUB PRODUCT AND METHOD or MAKING THE SAME. Patent dated August 30, 1932. Disclaimer filed July 7, 1934, by the assignee, The Patent and Licensing Corporation.

Hereby enters this disclaimer to that part of the specification of the aforesaid Letters Patent which consists of claims 5, 6, 7, 13, 14, and 15 which are in the following words, to wit: a

5. The method of manufacturin a fibrous product which com rises shredding fibrous material'containing not more fiaan 10 or cent moisture, witii a solid fusible binder to produce an intimate mixture, suspen ing said mixture in water, and forming a fibrous roduct from the wet pulp thus produced.

6. he method of manufacturing a fibrous product which comprises shredding a mixture of cellulosic fibrous material containing not more than 10 per cent moisture, filler, and a solid fusible binder to produce an intimate mixture, suspendin said mixture in water, and forming a fibrous product from the wet pulp thus pro need.

7. The method of manufacturing a. fibrous product which com rises shreddin fibrous material containing not more than 10 per cent moisture wit a solid fusible binder to produce an intimate mixture, beating a suspension of said mixture in water, forningba moist web from the pulp suspension produced, and forming a product from am we 13. In the herein-described process for manufacturing a fibrous product, the combination of steps which comprises shredding fibrous material containing not more than 10 per cent moisture with a solid fusible binder to produce an intimate mixture, and suspendin said mixture in water.

14. In t e herein-described process for manufacturing a fibrous article, the step which comprises shredding a mixture of fibrous material containing not more than 10 per cent of moisture, a solid fusible binder, and filler to produce an intimate mixture.

15. An article of manufacture comprising an irregular, intertan led mass of fibers and irregularly dispersed discrete particles of u fusible binder, said particles of binder adhering to said fibers and being adapted for subsequent fusion to bind the fibrous mass together in the fixed form ultimately desired.

[Oflicial Gazette August 7, 1.934.] 

